The neural basis for motor learning in the vestibulo-ocular reflex in monkeys

The vestibulo-ocular reflex (VOR) is a simple movement that undergoes motor learning in adult humans and monkeys. The time course of this learning suggests that it results from gradual changes in the efficacy of existing synapses. Available data indicate that the site of motor learning may be on cells in the brain stem that receive inhibition from the cerebellar flocculus. The flocculus does not appear to be the site of motor learning in the VOR, although it must be intact for learning to occur. We suggest that the output from the flocculus provides visual signals that guide the learning process at its target neurons. Parallels between learning in the VOR and in other motor systems suggest that the neural basis for learning and the role of the cerebellum may be similar in all systems.